Mega is only good for pirating content. Why were you using it not for pirated content?

OMG I have 1Gbit/s but it is restricted only to UA-IX (traffic inside our country only), ati 100Mbit/s worldwide is really a beast which I have never seen on my connection. Claiming that 100Mbit/s is "terrible" seems like lack of understanding of what terrible provider actually is.

For me terrible was when I downloaded few gigs of my backup data having only 10KB/s throughput because I did not want to pay and second of two sources of my back-up stopped hosting my data due to some emergency.

Perhaps your ISP is shaping/throttling your connection to MEGA?

Is this a typo or is this $100/year as in 8.33/month?

Mega is owned by Kim Dotcom who is about as trustworthy as John McAfee, this does not at all surprise me.